The present disclosure relates to a reagent management system, a method for automatically reconstituting reagents in order to carry out in-vitro diagnostic tests, and a reagent container holder to be used with the reagent management system.
In analytical laboratories, in particular, in-vitro diagnostic laboratories, a multitude of analyses on biological samples are executed in order to determine physiological and biochemical states of patients, which can be indicative of a disease, nutrition habits, drug effectiveness, organ function and the like.
Sample processing throughput, i.e., the number of biological samples analyzed per hour, as well as the number of different tests that can be carried out, are generally important. For laboratories handling thousands of samples each day, a small delay for each individual sample makes a substantial difference in terms of overall laboratory efficiency.
In order to meet this demand, optimal hardware design and efficient workflow planning are required in order to optimize the use of functional resources and maximize throughput. In particular, an automated system for in-vitro diagnostic analysis may be required to execute a large number of complex scheduled process operations, involving the repeated use of the same functional resources, possibly for different uses at different times of the process. Also, it is frequent that different tests require different test conditions, e.g., different reaction times, different types of reagents, different volumes, different detection times, and the like. The system should be also sufficiently flexible to new or changed user requests and be able to respond quickly to unpredicted situations like errors, failures and other unusual situations in the performance of a test.
Most diagnostics tests can be carried out with ready-to-use liquid reagents that have sufficiently long shelf-life in the liquid form, particularly in closed reagent containers. Many also have a sufficiently long open container stability under certain conditions, e.g., under refrigeration. On the other hand, some reagent types required to carry out other in-vitro diagnostic tests, such as some coagulation tests, are not stable in the liquid form.
Many of the coagulation reagents and controls that are required for coagulation testing come in a lyophilized formulation. Lyophilization refers to the process of freeze drying the liquid reagent which removes the liquid component and leaves a dry powder behind. As clot based coagulation testing requires the key components (e.g., tissue factor in the thromboplastin reagent) to be biologically active, lyophilization is necessary to preserve this function. In the lyophilized form, the tissue factor is preserved thereby giving the reagents a long shelf life. Before use in a test, the reagents need to be reconstituted with the exact amount of diluent (liquid) as prescribed in the package insert. However, it should be noted that once converted back into a liquid, the reagents can only be used for a very limited period. This limited period is referred to as the ‘open container stability time’. Whilst the shelf lives for closed containers are long (measured in months or years), the open container stability time of reagents and controls is typically short (measured in hours or days) and varies from reagent to reagent.
The lack of adherence to the storage conditions and times is a major source of error in the coagulation laboratory. Also, as these types of reagents are expensive they have to be used sparingly and with care.
Normally, lyophilized coagulation reagents are reconstituted manually just before use or, for example, at the beginning of the day based on an expected number of tests in the same day to be carried with those specific reagent types. This is not only time consuming and prone to errors, but also a real bottleneck with respect to throughput and workflow optimization, especially if the total volume of reconstituted reagents needed is underestimated and additional reagents have to be reconstituted. On the other hand, if the total volume of reconstituted reagents needed is overestimated, pricey and valuable reagents can be wasted once they have been reconstituted.
Therefore, there is a need for an automated reagent management system which provides higher processing throughput and workflow efficiency as well as optimal use of reagents, thereby ensuring reagent availability when needed and minimizing the risk of wasting valuable reagents through the use of a programmed controller that automatically selects the right reagent containers to be reconstituted at the right time and instructs an automatic reconstitution device to perform a series of reconstitution steps.